Wireless communication networks evolve towards higher data rates, together with improved capacity and coverage. This places new demands on these wireless communication networks.
In the 3rd Generation Partnership Project (3GPP) standardization body technologies like Global System for Mobile Communication (GSM), High-Speed Packet Access (HSPA) and Long Term Evolution (LTE) have been and are currently developed.
LTE is the latest technology standardised. It uses an access technology based on OFDM (Orthogonal Frequency Division Multiplexing) for the downlink (DL) and Single Carrier FDMA (SC-FDMA) for the uplink (UL). The resource allocation to mobile stations, in LTE denoted user equipment (UE), on both DL and UL is performed adaptively by the concept of fast scheduling, taking into account the instantaneous traffic pattern and radio propagation characteristics of each mobile station. Assigning resources in both DL and UL is performed in a so-called scheduler situated in a base station, in LTE often denoted eNodeB.
With the higher speeds a number of various applications that a user of the mobile station can be engaged in have evolved. It is for instance of interest for a user to involve him- or herself in online games, where small amounts of uplink data are transferred fairly often from the mobile station to another device involved in a game. Here the transferred data may be gaming commands and the other device may be another mobile station or another type of user terminal like a PC or even a server. Gaming is one example of delay-sensitive traffic. The increase of this delay-sensitive traffic and its significant share in the internet traffic leads to the radio interfaces of wireless communication systems having to meet various latency requirements to ensure that a mobile station user can enjoy the activities employing this type of traffic. Another example of delay-sensitive traffic is ping. Ping is for instance used to estimate the delay of a channel as well as to measure the performance in radio systems in order to for instance compare and/or rank different systems.
Setting up of traffic in a wireless communication network is often referred as allocation of resources. When resources are allocated to a mobile station desiring to send data in the uplink, there are normally a number of activities that have to be performed. First the mobile station sends a scheduling request (SR). This is followed by the base station responding with a grant, which grant includes information on what time/frequency resources the mobile station shall use. The mobile station then transfers a Buffer Status Report (BSR) after which the base station issues a grant for further data. It is not until it receives this further grant that the mobile station can transmit the actual data it intends. This process is time consuming, especially if the mobile station is to run through the process each time it desires to transfer data.
The transfer of uplink data is thus time consuming and puts a limit to the user enjoyment of the application employing delay-sensitive traffic. There is therefore a need for speeding up uplink communication of delay-sensitive traffic in wireless communication systems.
Some activities have previously been performed in relation to the above-mentioned access grants. WO 2009/126078 does for instance describe a method for use in a cellular system, in which there are controlling nodes which schedule control messages from users in a cell to the controlling node by transmitting uplink grants to the users. A controlling node here transmits a downlink control message to a user, and estimates, based on the nature of the downlink control message, the size of an up link control message in a response from the user and a transmit time when the user will be ready to transmit the control message, and transmits an up link grant to the user, designed to fit the estimated size of the control message from the user and the estimated transmit time. It can thus be seen that this document describes influencing access grants in relation to control messages sent by a mobile station.
There is in view of what has been described above a need for lowering the delay of uplink communication.